Endotracheal intubation, in which a tube is passed via the mouth or nose, through the larynx and into the trachea, is an important procedure in providing a positive airway in general medical practice to allow for the administration of anaesthesia or to provide air to the lungs. Endotracheal intubation may need to be performed for a variety of reasons, such as in the treatment of comatose patients where airways are liable to collapse due to reduced muscle tone, or, for example, in general anaesthesia wherein spontaneous respiration may be decreased or absent. In many of these cases, intubation tubes will need to be inserted by doctors or paramedics to unconscious patients in emergency situations. The procedure is further complicated by the risk of damage to the patient's teeth and the soft tissue of the throat. Considerable skill is therefore required when inserting an endotracheal tube in order to ensure that intubation is carried out in the quickest manner possible, without causing injury to the patient.
Endotracheal intubation is conventionally performed via direct laryngoscopy, in which a laryngoscope is used to restrain the patient's tongue and displace the epiglottis. This allows for direct visualisation of the larynx and the entrance to the trachea through the oral cavity, along with a clear passageway so that intubation may be more easily performed.
Traditional laryngoscopes comprise an elongate rigid blade, which may be curved or straight, extending from a handle, and typically include a light source, to illuminate the area of interest. In use, the laryngoscope blade is inserted through the oral cavity into the pharyngeal area, displacing the tongue and epiglottis. Once the laryngoscope is in position, an endotracheal tube is then inserted, via the nose or the oral cavity, alongside the laryngoscope blade and past the displaced epiglottis. Video laryngoscopes, employing a video camera located on or in the blade, or connected through a fibre optic bundle to a location on or in the blade, can provide further assistance when guiding the intubation tube into a patient's trachea.
Whilst visualisation of the intubation procedure has improved, the process of guiding the intubation tube into the trachea is still relatively cumbersome. The main problem with current intubation procedures is the difficulty in placing the tube. Various adjuncts, such as introducers, are known in the art for aiding this procedure as the introducer can be inserted prior to the more cumbersome intubating tube. However, there are still many cases where the introducer is accidentally placed into the oesophagus rather than the trachea, causing problems.
Introducers are firm guides, typically of small circumference, which are inserted into the larynx of the patient. Once the introducer is in place, the larger intubation tube is inserted over the introducer into the trachea. The introducer is then slidably removed from the trachea leaving the outer intubation tube in position. As introducers have some flexibility and/or malleability, they are particularly useful adjuncts to the intubation procedure when only part of the larynx is visible or when only the epiglottis can be seen. In use, the difference between the external diameter of the introducer and the internal diameter of the outer intubation tube should be fairly small as when greater differences between these diameters exist, the outer intubation tube can drag the introducer out of the airway. An example of a commonly used introducer is the Eschmann tracheal tube introducer (gum elastic bougie). This is a 60 cm long, 15 French Gauge flexible device with a J (coude) angle at its distal tip. This bougie can be passed into the trachea and, due to its flexible and malleable nature, is considered to be relatively atraumatic for the patient. The coude (bent) tip can also be used to sense the tracheal rings and thus to ensure that the bougie has not entered the oesophagus.
In order to direct the insertion of an intubation tube, it is known to provide guide means, for use with a laryngoscope blade. These guide means typically comprise a tube guide, for example, one or more channels which are of a sufficient diameter to house the intubation tube, and which are integrally formed with, or attached to the laryngoscope blade. Such guide channels typically extend along the majority of the length of the laryngoscope blade. It is also known from WO 2009/027669 (Aircraft Medical Limited) to provide a tube guide using spaced apart tube guiding members, reducing bulk.
In use, the intubation tube is inserted into the tube guide, and directed along its length into the trachea. Whilst this is a simple and effective means for introducing an intubation tube, in order to remove the laryngoscope and bougie once the intubation tube is in place, the laryngoscope blade must be slid back along the inserted tube towards the oral cavity, in order to separate the blade from the inserted tube. This is an awkward procedure as it requires the practitioner to hold both the laryngoscope and the inserted tube while withdrawing the blade, and can also be time-consuming, which is a significant disadvantage for a technique which is commonly used for medical procedures in which time can be of vital importance.
Furthermore, as the intubation tube is relatively large, some tube guides are very bulky. The size of the tube also obscures a user's view, even in cases where the laryngoscope is provided with video imaging, making insertion difficult. This is why introducers are often used to assist insertion but these are typically not guided into place.
The present invention provides improved guide means (such as a tube guide) which mitigates one or more of the limitations previously discussed.
Throughout this document the term blade portion should be read in a broad sense to cover not only laryngoscope blades but also to cover speculums or elements that are inserted into body cavities. Furthermore, whilst the term “bougie” is used throughout the specification, it will be understood that this is simply one example of a suitable introducer and that any suitable introducer is encompassed by the term.